Atacama Desert Habitat

The Atacama Desert is an irregular elongated strip of desert along the northwest coast of Chile, essentially bounded by the Pacific Ocean on the west. It extends nearly 1600 kilometres (km) and reaches a maximum width of 180 km. In many areas rainfall has never been recorded, and the Atacama is considered one of the driest deserts in the world. Consequently, an extremely arid, almost barren, landscape predominates. Despite the aridity of this desert, some cacti (Eulychnia), perennials (Nolana), and mesquite (Prosopis) occur in basins where occasional water accumulation occurs. Relatively few animal species have adapted to this arid environment and therefore, faunal diversity and density is extremely low, while endemism is high. Even bacteria are scarce, and in many portions of the desert insects and fungi are absent. While bacterial occurrences are even scarce compared to other deserts, there are a number of extremophiles and lithic microbial communities which specialize in exploiting minerals such as dolomite, quartz, gypsum, halite and limestone.

Few fauna have adapted to successfully inhabit this extremely arid habitat. Only 120 vertebrate taxa are found in the ecoregion. There are approximately 550 species of vascular plants representing 225 genera and 80 families in the lomas formations. The most diverse families are the Asteraceae, Nolanaceae, Cactaceae, Boraginaceae, and Apiaceae. Plant endemism is very high (in excess of 60 percent). Three cacti are endemic to the northern part of the Atacama Desert; in particular these endemic plants include Eulychnia iquiquensis and Copiapoa spp. Endemic shrubs of the ecoregion include Berberis litoralis, Anisomeria littoralis, Atriplex taltalensis, Adesmia viscidissima, Croton chilensis, Nicotiana solanifolia, Teucrium nudicaule, Monttea chilensis, Stevia trifida, Senecio almeidae and Gutierrezia taltalensis. Endemic plants near Tocopilla are Malesherbia tocopillana, Mathewsia collina and Nolana tocopillensis.

Several birds, such as the Rufous-collared Sparrow (Zonotrichia capensis) and the Blue-black Grassquit (Volatinia jacarina) visit the lomas at the onset of austral winter, when many insect pupae hatch. The lomas in bloom are also visited by several species of hummingbirds (e.g., Rhodopis spp., Myrtis spp., and Thaumastura spp.). There are six restricted species of birds found in the north of this ecoregion and the Sechura Desert ecoregion; these birds include the Chilean Woodstar (Eulidia yarrellii), Thick-billed Miner (Geositta crassirostris), White-throated Earthcreeper (Upucerthia albigula), Cactus Canastero (Asthenes cactorum), Slender-billed Finch (Xenospingus concolor, and Tamarugo Conebill (Conirostrum tamarugense). The Andean Condor is also found here in the Atacama. The Chilean Woodstar, Slender-billed Finch, and Tamarugo Conebill are examples of threatened species occurring in the ecoregion.

The South American Leaf-toed Gecko (Phyllodactylus gerrhopygus), found only in southern Peru and northern Chile, occurs in the Atacama Desert. Near-endemic amphibians are represented by the Vallenar toad (Rhinella atacamensis), which occurs in and near oases and streams year-around. Breeding occurs in permanent pools (including livestock water tanks), streams and rivers.Eggs are laid in long strings, and the larvae develop where these were laid. R. atacamensis achieves is highest altitude occurrence at 2574 metres near Mostazal.